bitte helft mir.

$${\sqrt{{{\mathtt{2.5}}}^{{\mathtt{2}}}{\mathtt{\,-\,}}{{\mathtt{3.1}}}^{{\mathtt{2}}}{\mathtt{\,\small\textbf+\,}}{{\mathtt{1.9}}}^{{\mathtt{2}}}}} = {\frac{{\mathtt{1}}}{{\mathtt{2}}}} = {\mathtt{0.5}}$$